<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Db
 * @subpackage Adapter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Sqlite.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Db_Adapter_Pdo_Abstract
 */
require_once 'Zend/Db/Adapter/Pdo/Abstract.php';

/**
 * Class for connecting to SQLite2 and SQLite3 databases and performing common operations.
 * @category Zend
 * @package Zend_Db
 * @subpackage Adapter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Db_Adapter_Pdo_Sqlite extends Zend_Db_Adapter_Pdo_Abstract {

    /**
     * PDO type
     * @var string
     */
    protected $_pdoType = 'sqlite';

    /**
     * Keys are UPPERCASE SQL datatypes or the constants
     * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.
     * Values are:
     * 0 = 32-bit integer
     * 1 = 64-bit integer
     * 2 = float or decimal
     * @var array Associative array of datatypes to values 0, 1, or 2.
     */
    protected $_numericDataTypes = array(Zend_Db::INT_TYPE => Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE, Zend_Db::FLOAT_TYPE => Zend_Db::FLOAT_TYPE, 'INTEGER' => Zend_Db::BIGINT_TYPE, 'REAL' => Zend_Db::FLOAT_TYPE);

    /**
     * Constructor.
     * $config is an array of key/value pairs containing configuration
     * options. Note that the SQLite options are different than most of
     * the other PDO adapters in that no username or password are needed.
     * Also, an extra config key "sqlite2" specifies compatibility mode.
     * dbname => (string) The name of the database to user (required,
     * use :memory: for memory-based database)
     * sqlite2 => (boolean) PDO_SQLITE defaults to SQLite 3. For compatibility
     * with an older SQLite 2 database, set this to TRUE.
     * @param array $config An array of configuration keys.
     */
    public function __construct (array $config = array()) {
        if (isset ($config['sqlite2']) && $config['sqlite2']) {
            $this -> _pdoType = 'sqlite2';
        }
        // SQLite uses no username/password. Stub to satisfy parent::_connect()
        $this -> _config['username'] = null;
        $this -> _config['password'] = null;
        return parent::__construct ($config);
    }

    /**
     * Check for config options that are mandatory.
     * Throw exceptions if any are missing.
     * @param array $config
     * @throws Zend_Db_Adapter_Exception
     */
    protected function _checkRequiredOptions (array $config) {
        // we need at least a dbname
        if ( ! array_key_exists ('dbname', $config)) {
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ("Configuration array must have a key for 'dbname' that names the database instance");
        }
    }

    /**
     * DSN builder
     */
    protected function _dsn () {
        return $this -> _pdoType . ':' . $this -> _config['dbname'];
    }

    /**
     * Special configuration for SQLite behavior: make sure that result sets
     * contain keys like 'column' instead of 'table.column'.
     * @throws Zend_Db_Adapter_Exception
     */
    protected function _connect () {
        /**
         * if we already have a PDO object, no need to re-connect.
         */
        if ($this -> _connection) {
            return;
        }
        parent::_connect ();
        $retval = $this -> _connection -> exec ('PRAGMA full_column_names=0');
        if ($retval === false) {
            $error = $this -> _connection -> errorInfo ();
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ($error[2]);
        }
        $retval = $this -> _connection -> exec ('PRAGMA short_column_names=1');
        if ($retval === false) {
            $error = $this -> _connection -> errorInfo ();
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ($error[2]);
        }
    }

    /**
     * Returns a list of the tables in the database.
     * @return array
     */
    public function listTables () {
        $sql = "SELECT name FROM sqlite_master WHERE type='table' " . "UNION ALL SELECT name FROM sqlite_temp_master " . "WHERE type='table' ORDER BY name";
        return $this -> fetchCol ($sql);
    }

    /**
     * Returns the column descriptions for a table.
     * The return value is an associative array keyed by the column name,
     * as returned by the RDBMS.
     * The value of each array element is an associative array
     * with the following keys:
     * SCHEMA_NAME => string; name of database or schema
     * TABLE_NAME => string;
     * COLUMN_NAME => string; column name
     * COLUMN_POSITION => number; ordinal position of column in table
     * DATA_TYPE => string; SQL datatype name of column
     * DEFAULT => string; default expression of column, null if none
     * NULLABLE => boolean; true if column can have nulls
     * LENGTH => number; length of CHAR/VARCHAR
     * SCALE => number; scale of NUMERIC/DECIMAL
     * PRECISION => number; precision of NUMERIC/DECIMAL
     * UNSIGNED => boolean; unsigned property of an integer type
     * PRIMARY => boolean; true if column is part of the primary key
     * PRIMARY_POSITION => integer; position of column in primary key
     * IDENTITY => integer; true if column is auto-generated with unique values
     * @param string $tableName
     * @param string $schemaName OPTIONAL
     * @return array
     */
    public function describeTable ($tableName, $schemaName = null) {
        $sql = 'PRAGMA ';
        if ($schemaName) {
            $sql .= $this -> quoteIdentifier ($schemaName) . '.';
        }
        $sql .= 'table_info(' . $this -> quoteIdentifier ($tableName) . ')';
        $stmt = $this -> query ($sql);
        /**
         * Use FETCH_NUM so we are not dependent on the CASE attribute of the PDO connection
         */
        $result = $stmt -> fetchAll (Zend_Db::FETCH_NUM);
        $cid = 0;
        $name = 1;
        $type = 2;
        $notnull = 3;
        $dflt_value = 4;
        $pk = 5;
        $desc = array();
        $p = 1;
        foreach ($result as $key => $row) {
            list ($length, $scale, $precision, $primary, $primaryPosition, $identity) = array(null, null, null, false, null, false);
            if (preg_match ('/^((?:var)?char)\((\d+)\)/i', $row[$type], $matches)) {
                $row[$type] = $matches[1];
                $length = $matches[2];
            } else 
                if (preg_match ('/^decimal\((\d+),(\d+)\)/i', $row[$type], $matches)) {
                    $row[$type] = 'DECIMAL';
                    $precision = $matches[1];
                    $scale = $matches[2];
                }
            if ((bool) $row[$pk]) {
                $primary = true;
                $primaryPosition = $p;
                /**
                 * SQLite INTEGER primary key is always auto-increment.
                 */
                $identity = (bool) ($row[$type] == 'INTEGER');
                 ++ $p;
            }
            $desc[$this -> foldCase ($row[$name])] = array('SCHEMA_NAME' => $this -> foldCase ($schemaName), 'TABLE_NAME' => $this -> foldCase ($tableName), 'COLUMN_NAME' => $this -> foldCase ($row[$name]), 'COLUMN_POSITION' => $row[$cid] + 1, 'DATA_TYPE' => $row[$type], 'DEFAULT' => $row[$dflt_value], 'NULLABLE' =>  ! (bool) $row[$notnull], 'LENGTH' => $length, 'SCALE' => $scale, 'PRECISION' => $precision, 'UNSIGNED' => null, // Sqlite3 does not support unsigned data
'PRIMARY' => $primary, 'PRIMARY_POSITION' => $primaryPosition, 'IDENTITY' => $identity);
        }
        return $desc;
    }

    /**
     * Adds an adapter-specific LIMIT clause to the SELECT statement.
     * @param string $sql
     * @param integer $count
     * @param integer $offset OPTIONAL
     * @return string
     */
    public function limit ($sql, $count, $offset = 0) {
        $count = intval ($count);
        if ($count <= 0) {
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ("LIMIT argument count=$count is not valid");
        }
        $offset = intval ($offset);
        if ($offset < 0) {
            /**
             *
             * @see Zend_Db_Adapter_Exception
             */
            require_once 'Zend/Db/Adapter/Exception.php';
            throw new Zend_Db_Adapter_Exception ("LIMIT argument offset=$offset is not valid");
        }
        $sql .= " LIMIT $count";
        if ($offset > 0) {
            $sql .= " OFFSET $offset";
        }
        return $sql;
    }

}
